Power-split transmissions of this type are used for example in working machines such as wheel loaders and dumpers. It is also possible, however, to use such transmissions in trucks or passenger cars.
DE 10356462 A1 discloses a control method for a motor vehicle with an electric motor, wherein first, by way of inputs via an on-board computer, a transmission characteristic also known as a Transmission Mode is selected, and thereafter, by way of a further selector lever, parameters of the transmission are varied, these parameters consisting of a ratio of traction force to speed.
These parameters are also often referred to as the Relationship Contour. The driver therefore has first to select the particular transmission characteristic, which can for example be the characteristic of a hydrodynamic change-speed transmission or a manually shifted transmission, and thereafter the driver must additionally select the ratio of traction force to speed by way of a further input switch.
U.S. Pat. No. 8,843,285 B2 discloses a motor vehicle with an electric motor, which, as in DE 10356462 A1, selects a transmission characteristic or Transmission Mode by means of a first switch, in order then, after that, to select the traction force to speed ratio by way of a second switch. Thus, the driver first selects whether the vehicle is to behave as a hydrodynamic vehicle or as a hydrostatic vehicle, in order then to select the ratio of traction force to speed.